The present invention relates to a wheel suspension for rear wheels of motor vehicles, especially passenger motor vehicles equipped with front wheel steering, which includes a wheel carrier for each rear wheel that is connected by way of wheel guide members with the vehicle body or the like, of which at least three are constructed as cross guide members extending at least approximately in the vehicle transverse direction.
A wheel suspension of this general type suitable, in particular, for driven rear wheels is known from the EP-OS No. 193090, in which with an arrangement having two lower cross guide members, the rear cross guide member supports the support spring constructed as coil spring and a shock absorber, whereas nothing is indicated with an arrangement having two upper cross guide members where the support spring is then to be supported. The known wheel suspension includes a forwardly projecting longitudinal guide member which is secured at its forward end at the vehicle body elastically yieldingly in the vehicle longitudinal direction. By reason of this bearing support and the steering geometry, wheel displacements are possible under the influence of braking and driving forces which change the track width position of the rear wheel. An intentional steering of the rear wheels is not attainable with this prior art wheel suspension.
An intentional steering is possible with another known wheel suspension for front wheel driven vehicles in which a spring leg, a longitudinal guide member and two cross guide members arranged parallel to one another and one behind the other at a distance from one another are provided at each rear wheel-wheel carrier, of which the forward cross guide member is secured with its outer end at the lower end of the spring leg and with its inner end at the vehicle body whereas the rear cross guide member is connected with its outer end by way of a steering lever also with the lower end of the spring leg and with its inner end with a thrust rod actuatable hydraulically or by an electric motor (DE-OS No. 35 07 098). However, this prior art wheel suspension is costly. In this prior art construction, the vehicle body is supported by way of the support springs of the spring legs.
An intentional steering is also provided in a further known wheel suspension for driven rear wheels of passenger motor vehicles with four-wheel steering, in which a support spring supporting the vehicle body which is constructed as coil spring and is arranged in front of the wheel drive shaft, is supported on the wheel side on an inclined guide member serving as wheel guide member which is arranged underneath the wheel drive shaft, is constructed fork-shaped and is elastically supported at the vehicle body by way of one bearing in front and one bearing behind the wheel drive shaft and for steering purposes can be displaced in its plane by means of an adjusting motor under deformation of the elastic bearings (EP-OS No. 96345, FIGS. 16 and 17). In this prior art wheel suspension, a shock absorber is provided as further wheel guide member. A kinematically exact steering is not assured by reason of the deformability of the elastic bearing.
The present invention is concerned with the task to provide a wheel suspension of the aforementioned type which enables an intentional steering of the rear wheels while maintaining the compact construction which is known from the wheel suspension mentioned first hereinabove.
The underlying problems are solved according to the present invention in that with an arrangement having two lower cross guide members, the rear cross guide member and with an arrangement having two upper cross guide members, the forward cross guide member supports the support spring and for the limited steering of the rear wheels the supporting cross guide member is connected at its inner end with a thrust rod that is operatively connected with an adjusting motor, and is displaceable in the vehicle transverse direction by the adjusting motor. It is achieved by the present invention with simple means that an exact steering can be carried out at will within the extent limited for the steering of the rear wheels by means of a wheel suspension which altogether requires only a small installation space and in which in particular the space between the rear wheels can be utilized for other purposes, for example, as luggage space.